The invention relates to a synchronous rectifier comprising a rectifier diode; a transistor having a control electrode, and a main current path between a first main electrode and a second main electrode of the transistor, which main current path is coupled in parallel with the rectifier diode; and a control circuit coupled to the control electrode of the transistor.
Such a power supply is known from the European Patent Specification EP 0 464 246 A1. Said Specification describes a power supply which uses the synchronous rectifier. The power supply comprises switching means which are periodically turned on and turned off, as a result of which an alternating current flows through a first winding of a transformer. This results in an alternating voltage being induced in a second winding of the transformer, which alternating voltage is subsequently rectified. For this purpose, the transistor is turned on and turned off at suitable instants (synchronous rectification). This requires a correct timing for the transistor. This is complicated. Therefore, there is a need for solutions to this timing problem.